Primality proof for n = 13909529:

Take b = 2.

b^(n-1) mod n = 1.

1738691 is prime.
b^((n-1)/1738691)-1 mod n = 255, which is a unit, inverse 12327661.

(1738691) divides n-1.

(1738691)^2 > n.

n is prime by Pocklington's theorem.